Windscreen wiper arm, particularly for automobiles

ABSTRACT

A windscreen wiper arm, particularly for automobiles, that is able to oscillate upwardly and downwardly between a downward position and an upward position. One end of the windscreen wiper arm is adapted to be pivotally connected to a mounting head mounted on a drive shaft. Another end of the windscreen wiper arm is rigidly connected to an adapter adapted to be connected to an elongated wiper blade to be placed in abutment with a windscreen to be wiped. The adapter, at the location of its connection to the wiper blade, has a U-shaped cross-section with a base and two spaced-apart legs. The U-shaped cross-section is preferably mounted offset in a plane of the base relative to a longitudinal axis of the windscreen wiper arm. The windscreen wiper arm is provided with a nozzle for spraying a washing liquid onto the windscreen to be wiped. The nozzle is detachably connected to the adapter through a key hole connection.

BACKGROUND OF THE INVENTION

German patent publication no. 34 33 106 (SWF Auto-Electric GmbH)discloses an oscillating windscreen wiper arm comprising an arm memberpivotally connected to a mounting head by means of a pivot pin. The armmember has a substantially U-shaped cross-section near the pivot pinhaving two side walls. A part of the mounting head extends between theside walls and beyond the pivot pin. A spring is hooked with its firstend on a pin on the mounting head. The arm member is connected to awiper rod, where one end of the wiper rod extends inside the U-shapedcross-section of the arm member. The side walls of the arm member arelocally folded around the wiper rod, while a holder is folded around theend of the wiper rod. The spring of this prior art windscreen wiper armis hooked with its first end on the pin on the mounting head and withits second end on two eyes of the holder.

A disadvantage of the windscreen wiper arm known from the above Germanpatent publication is that the windscreen wiper arm is often used incombination with a nozzle fixedly mounted on (or below) a bonnet of acar for spraying a washing liquid onto the car's windscreen to be wiped.In practice it has become apparent that the windscreen cannoteffectively be cleaned by a combination of the known windscreen wiperarm and the nozzle, as the nozzle emits the washing fluid at a largedistance relative to the windscreen, so that a relatively large amountof the washing fluid does not effectively reach a wiping pattern on thewindscreen to be wiped. Further, it has become apparent that in theprior art, a large amount of liquid (consumption) is required in anattempt to clean the windscreen to be wiped. Further, if the washingfluid is spread onto the car's body instead of onto the windscreen to bewiped, it may damage the car. Indeed, ethanol, methanol and othercomponents of the washing fluid are believed to have a corrosive effecton paint, rubber, car wax and plastics, for example.

SUMMARY OF THE INVENTION

It is an object of the invention to obviate these disadvantages, in thesense that at minimum costs—without using complex machinery andadditional tools—a simple windscreen wiper arm is proposed toeffectively clean a windscreen to be wiped, without damaging parts of acar, where less washing liquid is required to clean the windscreen to bewiped.

The present invention relates to a windscreen wiper arm, particularlyfor automobiles, that is able to oscillate upwardly and downwardlybetween a downward position and an upward position. One end of thewindscreen wiper arm is arranged to be pivotally connected to a mountinghead mounted on a drive shaft. Another end of the windscreen wiper armis rigidly connected to an adapter arranged to be connected to anelongated wiper blade to be placed in abutment with a windscreen to bewiped. The adapter, at the location of its connection to the wiperblade, has a U-shaped cross-section with a base and two spaced-apartlegs. The U-shaped cross-section is preferably mounted offset in a planeof the base relative to a longitudinal axis of the windscreen wiper arm.

In the framework of the present invention the windscreen wiper arm maycomprise a wiper arm member having a substantially U-shapedcross-section, as well as a wiper rod. One end of the wiper arm memberis arranged to be pivotally connected to the mounting head. Another endof the wiper arm member is rigidly connected to the wiper rod. One endof the wiper rod extends inside the U-shaped cross-section of the wiperarm member, and another end of the wiper rod is arranged, through theadapter, to be connected to the elongated wiper blade to be placed inabutment with a windscreen to be wiped.

The present invention particularly relates to a windscreen wiper arm foran elongated wiper blade in the form of a so-called flat blade, where anelastic elongated carrier element is provided. The flat blade includesat least one longitudinal groove, in which groove a longitudinal strip(also called a “flexor”) of the carrier element is disposed. There is norestriction to the use of only one longitudinal strip forming theelastic carrier element that is particularly located in a centrallongitudinal groove of the flat blade. Instead, the carrier element mayalso comprise two longitudinal strips, where the strips are disposed inopposite longitudinal grooves of the flat blade. The groove(s) may beclosed at one outer end. The flat blade comprises a connecting device(also indicated as a “connector”) arranged to be connected to thewindscreen wiper arm. Preferably, the connector is made in one piece,also called a “one piece connector.” The flat blade comprises a spoilerat a side thereof facing away from the windscreen to be wiped, where theflat blade and the spoiler are preferably made in one piece throughextrusion. The present invention is not limited to flat blades, but canalso be applied in traditional windscreen wiper devices having yokes.

The mounting head is usually fixed for rotation to the shaft. The shaftis rotatable alternately in a clockwise and in a counter-clockwise sensecarrying the mounting head into rotation. Thus, in turn the mountinghead draws the connecting device into rotation and thereby moves theflat blade. In the alternative, the mounting head is fixed fortranslation to a carriage, where the carriage can be translatedalternately in a one linear direction and in another counter lineardirection carrying the mounting head into translation. The presentinvention can therefore be used for circular or linear movement of themounting head.

According to the invention, a windshield wiper arm is provided with anozzle for spraying a washing liquid onto the windscreen to be wiped.The nozzle is detachably connected to the adapter through a key holeconnection. A keyhole connection enables a rapid and reliable joining ofthe nozzle and the adapter. By connecting the nozzle directly to theadapter of the windscreen wiper arm, the nozzle is not only fixed to thewindscreen wiper arm in a reliable and controllable manner, althoughdetachably in case of repair or replacement of the nozzle, but thenozzle is located at a very small distance relative to the windscreen tobe wiped and is allowed to directly follow any oscillatory movement ofthe windscreen wiper arm, so that the washing fluid exiting the nozzlecan be effectively sprayed thereon, with all positive consequencesinvolved as to effective cleaning of the windscreen to be wiped and safevisibility for a driver. Further, the nozzle may be used as a firstnozzle in combination with a second nozzle located on the windscreenwiper arm for spraying a washing liquid onto the windscreen to be wiped.In that case the washing liquid is sprayed from at least two locations(on the adapter and on the windscreen wiper arm) onto the windscreen tobe wiped, namely washing liquid exiting from the first nozzle connectedto the adapter, as well as washing liquid exiting from the second nozzleconnected to the windscreen wiper arm. Thus, the windscreen can becleaned efficiently over a very large wiping area thereof, particularlyat high speeds. In that case, the first and second nozzles arepreferably connected to only one inlet for the washing fluid, so thatthe first and second nozzles are in liquid contact with each other.

The present invention is not restricted to cars, but also refers to railcoaches and other (fast) vehicles.

In a preferred embodiment of a windscreen wiper arm in accordance withthe invention, the key hole connection comprises a slot having anenlarged hole, a reduced hole and a restricted neck interconnecting theenlarged hole and the reduced hole. The key hole connection alsocomprises a protrusion. The slot and the protrusion are arranged to berelatively movable via the restricted neck between a first position,where the protrusion passes through the enlarged hole with play, and asecond position, where the protrusion passes through the reduced holeunder deformation. Preferably, the protrusion is arranged to passthrough the reduced hole under elastic deformation in order to besnapped (“clipped”) inside the restricted hole. The relative movement ispreferably a sliding movement in a longitudinal direction of thewindscreen wiper arm.

In a further preferred embodiment of a windscreen wiper arm according tothe invention the protrusion comprises a shank in the first positionpassing through the enlarged hole with play and in the second positionpassing through the reduced hole under deformation, and an enlarged headabutting an inner wall of the reduced hole.

To enhance its elasticity in order to snap through the reduced hole, theprotrusion preferably has an inner hole, preferably a concentric innerhole inside the shank.

In a further preferred embodiment of a windscreen wiper arm inaccordance with the invention the enlarged hole and the reduced hole areblind holes. In the alternative, the enlarged hole and the reduced holeare through holes.

In a further preferred embodiment of a windscreen wiper arm according tothe invention the protrusion is formed on one of the adapter and thenozzle, and the slot is formed on the other of the adapter and thenozzle. Particularly, one of the legs of the U-shaped cross-section ofthe adapter comprises the slot, and the nozzle comprises the protrusionextending inwardly in a direction towards the adapter. More inparticular, one of the legs of the U-shaped cross-section of the adaptercomprises two slots, and the nozzle comprises two correspondingprotrusions extending inwardly in a direction towards the adapter.

In a further preferred embodiment of a windscreen wiper arm inaccordance with the invention the nozzle is detachably connected to theadapter at a lateral side of the windscreen wiper arm in use facingtowards the upward position. Hence, washing liquid sprayed by the nozzleonto the windscreen to be wiped is immediately washed away by the wiperblade. In the alternative, the nozzle is detachably connected to theadapter at a lateral side of the windscreen wiper arm in use facingtowards the downward position.

In a further preferred embodiment of a windscreen wiper arm according tothe invention the nozzle is made of a plastic material. The adapter isparticularly made of metal.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in more detail with reference tofigures illustrated in a drawing, wherein:

FIG. 1 shows details of a windscreen wiper device of the flat blade typeillustrating successive steps for fitting a windscreen wiper arm to aconnecting device of a wiper blade;

FIGS. 2A-2D show successive steps in connecting a nozzle to a windscreenwiper arm according to the invention;

FIGS. 3A-3D show details of the key hole connection shown in FIGS.2A-2D; and

FIG. 4 shows perspective views of the adapter and the nozzle of FIGS.2A-2D and 3A-3D with a cap (in a disassembled position) according to theinvention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a windscreen wiper device 1 of the flat blade typeincluding a wiper blade 2 having opposing longitudinal grooves 3 formedin the longitudinal sides of the wiper blade 2. Longitudinal strips 4(“flexors”) made of spring band steel are fitted in the longitudinalgrooves 3. The strips 4 form a flexible carrier element for the rubberwiper blade 2, which is thus biased in a curved position (the curvaturein operative position being that of a windscreen to be wiped). Thewindscreen wiper device 1 also includes a connecting device 5 of plasticmaterial for a windscreen wiper arm 6. The connecting device 5 comprisesclamping members 7 that are integral therewith, which engagelongitudinal sides of the strips 4 that face away from each other. Thus,the connecting device is firmly attached to the unit consisting of thewiper blade 2 and the strips 4. The windscreen wiper arm 6 is pivotallyconnected to the connecting device 5 about a pivot axis near one endthereof, and in the following manner. The connecting device 5 comprisestwo cylindrical protuberances 8 extending outwardly on either side ofthe connecting device 5. These protuberances 8 pivotally engage inidentically shaped recesses 9 of a plastic joint part 10. The joint part10 comprises a resilient tongue 11 extending outwardly, while thewindscreen wiper arm 6 has an identically shaped hole 12. While mountingthe windscreen wiper arm 6 onto the connecting device 5/joint part 10,the resilient tongue 11 is initially pushed in against a spring forceand then allowed to spring back into the hole 12, thus snapping theresilient tongue 11 into the hole 12. This is called a bayonetconnection. As shown, the joint part 10 has inwardly bent edges 13serving to further enhance the retention of the connecting device5/joint part 10 onto the windscreen wiper arm 6 in the verticaldirection.

FIGS. 2A-2D show successive steps in connecting a nozzle 18 to awindscreen wiper arm 6 according to the invention. The windscreen wiperarm 6 may be connected to a connecting device 5 and/or joint part 10through a bayonet connection, as explained in relation to FIG. 1. Thewindscreen wiper arm 6 is able to oscillate upwardly and downwardlybetween a downward position and an upward position. One end of thewindscreen wiper arm is arranged to be pivotally connected to a mountinghead mounted on a drive shaft (not shown), and another end of thewindscreen wiper arm 6 is rigidly connected to an adapter 14 arranged tobe connected to an elongated wiper blade (not shown) to be placed inabutment with a windscreen to be wiped. As shown, the adapter 14, at thelocation of its connection to the wiper blade, has a U-shapedcross-section with a base 15 and two spaced-apart legs 16,17. In thiscase, the U-shaped cross-section is mounted offset in a plane of thebase 15 relative to a longitudinal axis of the windscreen wiper arm 6.

According to the invention and as depicted in FIGS. 2A-2D, thewindscreen wiper arm 6 is provided with a nozzle 18 for spraying awashing liquid onto the windscreen to be wiped. The nozzle 18 isdetachably connected to the adapter 14 through a key hole connection.The key hole connection comprises two slots 19,20 in one leg 17 of theU-shaped cross-section of the adapter 14. Referring to FIG. 3B, eachslot 19,20 has an enlarged hole 21, a reduced hole 22 and a restrictedneck 23 interconnecting the enlarged hole 21 and the reduced hole 22.Referring to FIGS. 2A-2D, the key hole connection also comprises a twoprotrusions 24,25 extending inwardly from a wall of the nozzle 18.Referring to FIGS. 3A-3D, each protrusion 24,25 includes a shank 26 andan enlarged head 27. Each slot 19,20 and its corresponding protrusion24,25 are arranged to be relatively movable via the restricted neck 23between a first position (FIGS. 2C and 3C), where the protrusion 24,25passes through the enlarged hole 21 with play, and a second position(FIGS. 2D and 3D), where the protrusion 24,25 passes through the reducedhole 22 under elastic deformation. As depicted in FIGS. 3A-3D, theenlarged heads 27 abut a chamfered inner wall of the reduced hole 22 inthe second position. To enhance its elasticity in order to snap throughthe reduced hole 22, each protrusion 24,25 preferably has an inner hole28, preferably a concentric inner hole inside the shank 26.

FIGS. 3A-3D show the perspective details of FIGS. 2A-2D, wherecorresponding parts have been designated with the same referencenumerals.

FIG. 4 shows perspective views of the adapter 14 and the nozzle 18 ofFIGS. 2A-2D and 3A-3D where corresponding parts have been designatedwith the same reference numerals. As shown, the nozzle 18 has anelongated shape, and is provided with an inlet 29 for washing liquid.The inlet 29 is directed towards the windscreen wiper arm 6 in order tobe connected to a supply channel (not shown) for the washing liquidlocated inside the windscreen wiper arm 6. Further, optionally, a cap 30is provided to be detachably fixed to the nozzle 18 through a snappingoperation. In this particular case the cap 30 is L-shaped and fullycovers the nozzle 18, so that the latter is not visible from theoutside.

The present invention is not restricted to the preferred variants shown,but extends also to other embodiments falling within the scope of theappended claims.

The invention claimed is:
 1. A windscreen wiper arm comprising: anadapter adapted to be connected to an elongated wiper blade to be placedin abutment with a windscreen to be wiped, wherein said adapter, at alocation of its connection to the wiper blade, has a U-shapedcross-section with a base and two spaced-apart legs; and a nozzle forspraying a washing liquid onto the windscreen to be wiped, wherein saidnozzle is detachably connected to said adapter through a key holeconnection, wherein said key hole connection comprises: a slot having anenlarged hole, a reduced hole and a restricted neck interconnecting saidenlarged hole and said reduced hole; and a protrusion; wherein said slotand said protrusion are arranged to be relatively movable via saidrestricted neck between a first position in which said protrusion passesthrough said enlarged hole with play, and a second position in whichsaid protrusion passes through said reduced hole under deformation. 2.The windscreen wiper arm according to claim 1, wherein said protrusionis arranged to pass through said reduced hole under elastic deformationin order to be snapped inside said reduced hole.
 3. The windscreen wiperarm according to claim 1, wherein said protrusion has an inner hole. 4.The windscreen wiper arm according to claim 1, wherein said protrusioncomprises: a shank in said first position passing through said enlargedhole with play and in said second position passing through said reducedhole under deformation, and an enlarged head abutting an inner wall ofsaid reduced hole in said second position.
 5. The windscreen wiper armaccording to claim 1, wherein said enlarged hole and said reduced holecomprise blind holes.
 6. The windscreen wiper arm according to claim 1,wherein said enlarged hole and said reduced hole comprise through holes.7. The windscreen wiper arm according to claim 1, wherein saidprotrusion is formed on one of said adapter and said nozzle, and whereinsaid slot is formed on another of said adapter and said nozzle.
 8. Thewindscreen wiper arm according to claim 7, wherein one of said legs ofsaid U-shaped cross-section of said adapter comprises said slot, andwherein said nozzle comprises said protrusion extending inwardly in adirection towards said adapter.
 9. The windscreen wiper arm according toclaim 7, wherein one of said legs of said U-shaped cross-section of saidadapter comprises two slots, and wherein said nozzle comprises twocorresponding protrusions extending inwardly in a direction towards saidadapter.
 10. The windscreen wiper arm according to claim 1, wherein saidnozzle is detachably connected to said adapter at a lateral side of saidwindscreen wiper arm in use facing towards an upward position.
 11. Thewindscreen wiper arm according to claim 1, wherein said nozzle isdetachably connected to said adapter at a lateral side of saidwindscreen wiper arm in use facing towards a downward position.
 12. Thewindscreen wiper arm according to claim 1, wherein said nozzle comprisesa plastic material.
 13. The windscreen wiper arm according to claim 1,wherein said adapter comprises a metal material.
 14. The windscreenwiper arm according to claim 1, wherein said U-shaped cross-section ofsaid adapter is mounted offset in a plane of said base relative to alongitudinal axis of said windscreen wiper arm.
 15. A windscreen wiperarm comprising: an adapter adapted to be connected to an elongated wiperblade to be placed in abutment with a windscreen to be wiped, whereinsaid adapter, at a location of its connection to the wiper blade, has aU-shaped cross-section with a base and two spaced-apart legs; and anozzle for spraying a washing liquid onto the windscreen to be wiped,wherein said nozzle is detachably connected to said adapter through akey hole connection, wherein said key hole connection comprises: a slothaving an enlarged hole, a reduced hole and a restricted neckinterconnecting said enlarged hole and said reduced hole; and aprotrusion, wherein said protrusion has an inner hole and saidprotrusion is arranged to pass through said reduced hole under elasticdeformation in order to be snapped inside said reduced hole; whereinsaid slot and said protrusion are arranged to be relatively movable viasaid restricted neck between a first position in which said protrusionpasses through said enlarged hole with play, and a second position inwhich said protrusion passes through said reduced hole underdeformation.